SanDisk SDSDH-1024 Product Manual - Page 64

When CMD6 changes the bus behavior i.e. access mode the host is allowed to use

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Revision 2.2 Chapter 4 - SD Card Protocol Description SanDisk SD Card Product Manual support it. The host will check the SD_SPEC field in the SCR Register to recognize what version of the spec the card complies with before using CMD6. Important: It is mandatory for the SD Card to be based on v1.10 in order to support CMD6. CMD6 is valid under the Transfer State, though once selected by the switch command, all functions return to the default function after a power cycle, CMD6 or CMD0. Using CMD0 to reset a card will cause it to reset to Idle State and all functions switch back to the default. As a response to CMD6, the SanDisk SD Card will send an R1 response on the CMD line, and 512 bits of status on the DAT lines. The SD bus transaction considers this a standard single block read transaction and the time-out value of this command is 100ms, same as in read command. If a CRC error occurs on the status data, the host should issue a power cycle. CMD6 function switching period is within eight clocks after the end bit of status data. When CMD6 changes the bus behavior (i.e. access mode) the host is allowed to use the new functions (increase/decrease CLK frequency beyond the current max CLK frequency), at least eight clocks after at the end of the switch command transaction. In response to CMD0, the switching period is within eight clocks after the end bit of CMD0. When CMD6 has changed the bus behavior (i.e. access mode) the host is allowed to start the initialization process, at least eight clocks after at the CMD0. © 2004 SanDisk Corporation 4-20 12/08/04

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Chapter 4 – SD Card Protocol Description
Revision 2.2
SanDisk SD Card Product Manual
© 2004 SanDisk Corporation
4-20
12/08/04
support it. The host will check the SD_SPEC field in the SCR Register to recognize what
version of the spec the card complies with before using CMD6.
Important:
It is mandatory for the SD Card to be based on v1.10 in order to support CMD6.
CMD6 is valid under the Transfer State, though once selected by the switch command, all
functions return to the default function after a power cycle, CMD6 or CMD0.
Using
CMD0 to reset a card will cause it to reset to Idle State and all functions switch back to the
default.
As a response to CMD6, the SanDisk SD Card will send an R1 response on the CMD line,
and 512 bits of status on the DAT lines. The SD bus transaction considers this a standard
single block read transaction and the time-out value of this command is 100ms, same as in
read command. If a CRC error occurs on the status data, the host should issue a power
cycle.
CMD6 function switching period is within eight clocks after the end bit of status data.
When CMD6 changes the bus behavior (i.e. access mode) the host is allowed to use the
new functions (increase/decrease CLK frequency beyond the current max CLK frequency),
at least eight clocks after at the end of the switch command transaction.
In response to CMD0, the switching period is within eight clocks after the end bit of
CMD0. When CMD6 has changed the bus behavior (i.e. access mode) the host is allowed
to start the initialization process, at least eight clocks after at the CMD0.